I have same issue though I have not tested on multiple machines. Mybook non-response… I have a passport that works fine on all usb ports, no issues. What I found out that is interesting is that: With the Mybook, if I short power input (not USB, but power input) for a few seconds, then my Drive is immediately recognized on the next plug-in. (Seems like the input bleed resistor is bad; just a theory!!) This is the second MyBook that I have had these symptoms with.
I Plan to lobby for a Passport to replace; seems to be no issue with Passport.
Best Luck!
